Sweeping Machine and Compensation Method for Uneven Patches

ABSTRACT

A sweeping machine includes a housing, at least one circular broom disposed on the housing so as to be rotatable about an essentially vertical axis of rotation, and at least one roller supported on a ground. The roller is disposed in the housing of the sweeping machine by way of an axle bracket concentric with respect to the circular broom so that the roller may be rotated about the essentially vertical axis of rotation. A rolling movement of the roller along the ground is transmitted to the circular broom so that the circular broom rotates about the essentially vertical axis of rotation. Devices, which convert a rotating movement of the roller about the essentially vertical axis of rotation to an axial relative movement between the roller and the housing, are provided. The method and machine improve the running smoothness of the sweeping machine.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2006 011 216.4 filed Mar. 3, 2006, the entire disclosure of which is herein expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a sweeping machine including at least one circular broom which, rotatably about an essentially vertical axis of rotation, is disposed on a housing. Furthermore, the invention relates to a method of improving the running smoothness of a corresponding sweeping machine.

A sweeping machine is known, for example, from German Patent document DE 41 01 888 C2, which has two inwardly oppositely rotating circular brooms laterally arranged in the front area of a housing, and two rollers supporting the front area of the housing on a ground surface, the axle brackets of the two rollers being vertically adjustably held in the housing by way of supporting elements for adjusting the distance between the circular brooms and the ground. The laterally arranged circular brooms are driven by way of the rollers arranged inside the bristle ring. In the case of such a manually operable sweeping machine, uneven patches in the ground may interfere with the rolling movement of the rollers and, therefore, also the sweeping movement of the circular brooms.

If, by use of an axle bracket concentric with respect to the circular broom, the roller is disposed in the housing of the sweeping machine such that the roller can be rotated about the essentially vertical axis of rotation of the circular brooms, the roller will act as a trailing roller. As a result, it is achieved that the roller drives the circular broom independently of the moving direction in the same rotating direction. However, the rotatability of the axle bracket further interferes with the smooth running of the sweeping machine in the case of uneven patches in the ground.

It is therefore an object of the invention to provide a sweeping machine of the above-mentioned type whose running smoothness is improved, as well as a method of improving the running smoothness of a sweeping machine.

This task is achieved, according to the invention, by a sweeping machine including a housing, at least one circular broom which, rotatably about an essentially vertical axis of rotation, is disposed on the housing, and at least one roller supported on a ground. The roller is disposed in the housing of the sweeping machine by way of an axle bracket concentric with respect to the circular broom, so that the roller can be rotated about the essentially vertical axis of rotation, and a rolling movement of the roller along the ground can be transmitted to the circular broom, so that the circular broom rotates about the essentially vertical axis of rotation. Devices are provided, which convert a rotating movement of the roller about the essentially vertical axis of rotation to an axial relative movement between the roller and the housing. When, as a result of uneven patches in the ground, the roller encounters a major resistance, it will rotate about its essentially vertical axis of rotation toward the rear with respect to the moving direction of the sweeping machine. By use of the devices according to the invention, the rotating direction of the roller is converted to an axial movement between the roller and the housing, so that the housing and, thereby, also the circular broom disposed at the housing, are raised. This reduces the resistance applied by the circular broom during its movement and improves the running smoothness of the sweeping machine.

In a further development of the invention, a part having a groove with continuously rising flanks is non-rotatably arranged on the axle bracket, and a stop complementary to the groove is non-rotatably arranged on the housing, which stop engages at least partially in the groove. The part is rotated by a rotation of the axle bracket, so that the groove and the stop are rotated out of a mutually aligned orientation. Because of this rotation, the relative distance between the part and the stop, and thus also between the roller and the circular broom, is enlarged.

In a further embodiment of the invention, the groove has a V-shape. The V-shaped construction ensures a particularly good conversion of the rotating movement to an axial movement. However, in addition, it is also contemplated to form a U-shaped groove, or a groove having a blunt groove base, in the part.

In another embodiment of the invention, the part and the axle bracket are constructed in several pieces. As a result, the axle bracket and the part can, for example, be produced from different materials. It is also contemplated to construct the part in a cost-effective manner as a plastic injection-molded part. However, it is also contemplated to construct the part and the axle bracket at a joint component. This permits a reliable transmission of the rotating movement of the axle bracket to the part.

In a further embodiment of the invention, the stop is constructed as a slide having a sloping stop face facing the axle bracket, which slide can be displaced transversely to the axle bracket, so that the axial position of the roller can be adjusted relative to the housing. An adjusting of the slide is, for example, performed by means of a rotatable adjusting wheel or the like. As a result, an easy vertical adjustment is permitted, in which case at least partly identical components can be used for compensating uneven patches and for a vertical adjustment.

In another embodiment of the invention, the groove in the part is at least partially inclined toward the axis of rotation. As a result, it is prevented that, during a rearward movement of the sweeping machine, the resulting rotating movement of the roller about the axle bracket leads to a vertical adjustment of the circular broom and thus to an increase of the resistance or of the contact pressure of the circular broom.

In an advantageous embodiment of the invention, the sweeping machine includes two circular brooms, which can each be driven by way of at least one interior roller. The construction with two circular brooms leads to a particularly good sweeping result. In such an embodiment, both circular brooms are preferably vertically adjustable by way of a common device. In contrast, a conversion of the rotating movement to an axial movement as a result of disturbances is preferably implemented separately for each circular broom.

According to another embodiment of the invention, in addition and/or as an alternative, the circular broom may be rotated by a motor drive. In this case, use of a powerful motor drive reduces the effect of uneven patches on the running smoothness of the sweeping machine. The compensating mechanism according to the invention can therefore be constructed with a free-wheel element, which prevents a lifting of the housing because of uneven patches when the motor drive is powerful.

The object of the invention is further achieved by a method of operating a sweeping machine, in which a rotating movement of the roller about the essentially vertical axis of rotation is converted to an axial relative movement between the roller and the housing.

In the following, the invention will be described in the manner of examples by means of preferred embodiments. Uniform reference symbols will be used for identical components.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic lateral view of a sweeping machine according to the invention;

FIG. 2 is a schematic cross-sectional view of a circular broom and its drive along the displacing direction of the sweeping machine;

FIG. 3 is a schematic view of a device for converting a rotating movement of a roller for driving the circular broom to an axial relative movement between the roller and a housing of the sweeping machine;

FIG. 4 a is a schematic cross-sectional view of the device transversely to the displacing direction; and

FIG. 4 b is a schematic cross-sectional view of the device according to FIG. 4 a in a condition rotated by 180°.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic lateral view of a sweeping machine 1, in which parts of the housing 14 of the sweeping machine 1 are cut free. The illustrated sweeping machine includes two circular brooms 2 which are arranged in the front area of the housing and are each driven by way of an interior roller 3. Only one circular broom 2 and one roller 3 are visible in the figure. The sweeping machine 1 is manually guided by way of a grip 10. The roller 3 rotates as a result of the driving movement of the sweeping machine 1. The rolling movement of the roller 3 is converted to a rotating movement of the circular broom 2 about the axis 21. The axis 21 extends essentially vertically but, as illustrated, may be slightly sloping forward for an improved cleaning effect. In addition, the sweeping machine 1 may have a rotary brush 12, which further improves the sweeping effect. As schematically indicated by a double arrow, the height of the circular broom 2 can be adjusted with respect to the ground, which varies a contact pressure and thereby also a sweeping effect.

FIG. 2 is a schematic cross-sectional view of the circular broom 2 and its drive. The circular broom 2 includes a basic body 20 to whose edge 22 bristles 24 are fastened. The basic body 20 may cost-effectively be constructed as a plastic injection-molded part. It is non-rotatably connected with a shaft 26 by way of a clutch 25 and is disposed to be rotatable about the axis of rotation 21. The shaft 26 has a toothing 28, in which a worm gear engages. The worm gear 30 is non-rotatably connected with the roller 3, so that the rolling movement of the roller 3 is converted by way of the shaft 26 to a rotating movement of the circular broom 2 about the axis of rotation 21.

In the illustrated embodiment, the circular broom 2 is additionally constructed with another clutch 29, by way of which a gear wheel 4 can engage, for example, for a motor drive of the circular broom 2 (which motor drive is not shown). The clutches 25, 29 are preferably constructed as overrunning clutches. This, for example, has the effect that, in the case of a purely manual operation, the motor drive will not be pulled along by way of the roller 3.

The roller 3 is disposed on an axle bracket 32 such that it can be rotated about the axis of rotation 21. The roller 3 therefore acts as a trailing roller which, with respect to the moving direction of the sweeping machine illustrated in FIG. 1, always arranges itself behind the axis of rotation. This allows for the roller 3 to always drive the circular broom 2 in the same rotating direction.

Schematically illustrated uneven patches of the ground 6 cause a resistance at the roller 3 and/or at the circular broom 2, so that the roller 3 is rotated against the rotating direction of the circular broom 2 about the axis of rotation 21. This resistance at the roller 3 and/or at the circular broom has to be manually compensated by a user in the case of conventional sweeping machines.

In contrast, according to the invention, because of the resistance with respect to the sweeping movement, the distance of the circular broom 2 from the ground is enlarged and its moment of resistance to a moving of the sweeping machine is thereby reduced. For this purpose, a part 5 having a V-shaped groove 51 is arranged at the end of the axle bracket 32 facing the housing 14. It is contemplated that the axle bracket 32 is constructed of metal, while the part 5 is produced as a cost-effective plastic injection-molded part. The axle bracket 32 is non-rotatably connected with the part 5. A stop 16 complementary to the groove is constructed opposite the part at the housing 14.

The rotating movement of the roller 3 about the axis of rotation 21 causes a rotating of the part 5 with respect to the stop 16. As a result, the part 5 is displaced away from the stop 16 and thus from the housing 14. The displacement has the result that the housing 14 and thus the circular broom 2 connected with the latter are lifted relative to the ground. This reduces the torque to be applied for the sweeping movement of the circular broom 2. By appropriately coordinating the flank angle of the groove 51 with the size of the circular broom 2, the resistances at the roller 3 and the reduced torque are only compensated just enough so that an improved running smoothness is achieved.

FIG. 3 illustrates another embodiment of a part 5′ according to the invention for the conversion of the rotating movement of the axle bracket 32 to a relative movement between the axle bracket 32 and the housing 14. The part 5′ is also constructed with an essentially V-shaped groove 51′, the groove 51′ having a flat groove base 52. A stop 16′ complementary to the groove 51′ is constructed on the housing 14. As described above, this stop 16′ is displaced or braced away from the axle holder 32 because of the rotating movement of the part 5′.

Further, the part 5′ is constructed with clamping arms 54 for a non-rotatable fastening to the axle holder 32. The axle holder 32 is preferably constructed with flattenings (not shown) for the non-rotatable connection with the part 5′.

FIG. 4 a is a cross-sectional view of part 5 transversely to the displacement direction of the sweeping machine 1 illustrated in FIG. 1, and FIG. 4 b is a cross-sectional view of part 5 according to FIG. 4 a, part 5 being swiveled by 180°. As shown in FIGS. 4 a and 4 b, the groove 51 of part 5 is sloping in the direction of its axis. It is thereby achieved that the part 5 and the stop 16 contact one another only in a punctiform manner. And, when the axle bracket 32 illustrated in FIG. 2 is swiveled by 180°, the stop 16 and the groove 52 do not mutually lock, so that such a rotation does not change the distance of the circular broom illustrated in FIG. 2 from the ground.

A manually guided moving of the sweeping machine 1 can therefore also be carried out in both directions when a device according to the invention for improving the running smoothness is provided. As schematically illustrated in FIGS. 4 a and 4 b, the stop 16 is preferably also constructed with a slope and, by a displacement along the transverse direction Q, can therefore be used for a vertical adjustment of the axle bracket in the H direction.

The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the sprit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

1. A sweeping machine, comprising: a housing; at least one circular broom rotatable about an essentially vertical axis of rotation and disposed on the housing; at least one roller disposed in the housing by way of an axle bracket concentric with respect to the circular broom so that the roller is rotatable about the essentially vertical axis of rotation, and a rolling movement of the roller along a ground surface being transmissible to the circular broom so that the circular broom rotates about the essentially vertical axis of rotation; and a mechanical coupling device which converts a rotating movement of the roller about the essentially vertical axis of rotation to an axial relative movement between the roller and the housing.
 2. The sweeping machine according to claim 1, wherein the mechanical coupling device comprises a part, which is non-rotatably arranged on the axle bracket and has a groove with continuously rising flanks, and a stop non-rotatably arranged on the housing, the stop being complementary at least partially with respect to the groove and at least partially engaging in the groove.
 3. The sweeping machine according to claim 2, wherein the groove has a V-shape.
 4. The sweeping machine according to claim 2, wherein the part and the axle bracket have a multi-piece construction.
 5. The sweeping machine according to claim 3, wherein the part and the axle bracket have a multi-piece construction.
 6. The sweeping machine according to claim 2, wherein the stop is constructed as a slide with a sloping stop face facing the axle bracket, the stop being slidable transversely to the axle bracket, so that a distance of the circular broom to the ground is adjustable.
 7. The sweeping machine according to claim 3, wherein the stop is constructed as a slide with a sloping stop face facing the axle bracket, the stop being slidable transversely to the axle bracket, so that a distance of the circular brooms to the ground is adjustable.
 8. The sweeping machine according to claim 2, wherein the groove is sloped with respect to the axis of rotation.
 9. The sweeping machine according to claim 3, wherein the groove is sloped with respect to the axis of rotation.
 10. The sweeping machine according to claim 6, wherein the groove is sloped with respect to the axis of rotation.
 11. The sweeping machine according to claim 1, wherein two circular brooms are provided, which are each driven in opposite directions by the at least one roller, which is arranged interiorly thereof.
 12. The sweeping machine according to claim 1, further comprising a motor drive operatively coupled to rotate the circular broom.
 13. A method for operating a sweeping machine to improve a running smoothness, the sweeping machine including a housing, at least one circular broom rotatable about an essentially vertical axis of rotation and disposed on the housing, and at least one roller disposed in the housing by way of an axle bracket concentric with respect to the circular broom so that the roller is rotatable about the essentially vertical axis of rotation, the method comprising the acts of: transmitting a rolling movement of the roller along a ground surface to the circular broom so that the circular broom rotates about the essentially vertical axis of rotation; and converting a rotating movement of the roller about the essentially vertical axis of rotation to an axial relative movement between the roller and the housing.
 14. A sweeping machine, comprising: a housing; at least one circular broom rotatable about an essentially vertical axis of rotation and disposed on the housing; at least one roller disposed in the housing by way of an axle bracket concentric with respect to the circular broom so that the roller is rotatable about the essentially vertical axis of rotation, and a rolling movement of the roller along a ground surface being transmissible to the circular broom so that the circular broom rotates about the essentially vertical axis of rotation; and means for converting a rotating movement of the roller about the essentially vertical axis of rotation to an axial relative movement between the roller and the housing. 